Prague is great, take Wizz Air from Naples. We stayed at the Czech Inn, fabulous place with a great breakfast included and good price, but I do not know if it is kid friendly. Definitely go to Prague Caslte, at noon they have some kind of changing of the guard ceremony that was cool. You will find the astronomical clock in the historic area. The trams are easy to use to get around and there is a subway. I went to the Jewish cemetery which my husband did not, but I loved it. The museum of communism was kitchy but fun. There are tons of good beers of course and lots of meat to eat and my husband keeps talking about the jacket potatoes. One big thing are the pub crawls, many of which meet and leave from the astronomical clock, but sounds like you are taking the kids. Have fun.